Machine for manufacturing hollow rubber balls



- July 1, 1930. K. KUROKAWA I 1,769,741

MACHINE FOR MANUFACTURING HOLLOW RUBBER BALLS 1o theforemost portion ofa I @atented July 1, 1930 UNITED STATES xmisnxn xunomwa, or snmonosnxr,APAN MACHINE FOB EZAN'U'IFAG'JEURIN'G' HOLLOW RUBBER BALLS Applicationfiled December 21, 1927. Serial No. 241,614.

This invention relates to apparatus for making hollow rubber balls andhas for its object the provision of a machine comprisin means andelements adapted to take in *5 a ength of unvulcanized sheet rubber andcut it into pieces of proper size and to transform them intohemispherical segments ready for the formation of hollow balls. Theoperation of manufacture is such that strip of sheet rub her is cut'round, while being cut straight across the length of the strip at therearmost point of the portion, and the round piece of rubber so cut offis thereafter trans- 16 formed into a hemispherical segment by means ofa presser and mould heated by steam. It is obvious that such segment maybe readily used for the manufacture of a hollow ball. To remove thesegment out 20 from the mould, means is provided for slanting the mouldto a suflicient degree so that the segment 'may be easily detached fromit.

, According to the invention, segments of 95 rubber as referred to maybe produced in a continuous flow and consequently in a large number: andin order tomanufacture hollowballs from them, it is simply necessary tojoin together every two of them at a single circumferential lineencircling the border of their hemispherical body. Such characteristicsmake the invention considerably advantageous over the known machines andapparatus for manufacturing hollow rubber balls.

The known method of making a hollow ball from two segments embodies astage of operation in which around piece of sheet rubber is folded upinto a semicircular segment and then-pressed in the mould to betransformed into a hemispherical half of a hollow ball. The draw-back inthis method is the fact that it is impossible to obtain a segment ofeven thickness, and moreover that the segment is likely to becomewrinkled at the portion where it is folded up. It must also be pointedout that in the process the portion of the sheet rubber cut to wastedas. scrap is in no. small amount.

Hence econo y' in the raw be expected. v

, Hollow balls made from four segments have generally been disliked forthe reason that they have many joint places due to the unequalness inthe expanding powers, while being inflated, of such joints and of plainparts, they are finished in bad state and often impregnated with thecauses for leakage. According to the invention these defectsare entirelyobviated.

. The accompanying drawings-illustrate by way of example a hollow rubberball manufacturing machine embodying most appropriately the features ofthe invention: in

material cannot Fig. 1 is a vertical sectional elevational' view of themachine,

Fig. 2 is a side elevational view of the same, and

Figs. 3 seen on the lines A- -B and 0-D of Fig. 1 respectively.

In the drawings same reference numerals denote identical parts.

Referring to the drawings, the supporting frame 1 supports a table orbed 2 beneath which is provided a hemispherical mould 4: mounted on ahollow shaft 6'. The hollow shaft is journalled in bearings 7, 7 andcarand that,

t0 and 4 are sectional plan views as ries a pmion 8 that may mesh withthe toothed part 21 of a segment wheel 20 mounted on a spindle 19located below the hollow shaft. The hollow shaft 6 is connected at oneend with an outer tubing in order to take in steam and admit it into thesteam-jacket 5. In actual use, a number of I such elements are providedin series and arranged in such a manner that the outlet of the hollowshaft in the first unit may be connected to the inletof the hollow shaftin the second and so on, until the final hollow shaft opens to the air.

Right above the mould4 is supported a presser 12 having a hollowpresser-head provided on one side with a steam-inlet 9 and on the othera steam outlet 10. The presser 12 is attached tothe lower end of areciproeating stem 15 which is vertically slidably I held in position byan arm 14 upheld by a p downward stroke.

support 13 fixed on the bed 2. The upper an of the stem 15 is engagedwith the periphery of a disc 17 mounted eccentrically on a shaft 16.provided at the uppers most portion of the machine. The stem 15 itselfis at all times forced upwards by means of a ring 18.

On the support 13 and above the arm 14 .is mounted a forked arm whichfurther holds u a tubularcutter-casing 27 provided at the ower end witha cutting -element. As shown in the drawing, the resser, reciprocatingstem, and spring, re erred to, are all housed in the cutter-casing 27,whilst'the arm 14 projects through an ope 28 into the interior of thecutter-casing. e cuttar-casing is also encircled by a sp 29 andtherefore the former always ten to ilnove u vghards. As ak result, theupper ange o e casmg is ept in e ement with the peripheries of discs 30,3 3 the said discs eccentrically mounted on the shaft 16 in a certainangular relation with the 16. The cutting element of the on consists ofan annular edge 26 and a linear or straight 32, the dimeter of theannular g a little greater than the width of the inside hemisphere ofthe mould and the straight edge extending slightly longer than the saiddiof the annular edge. The straight edge is located at the right handside of the annular edge reference being had to Fi 1 of the dra wherethe sheet rubb r as 1s introduced.

The upper shaft 16 is provided with a crank and the lower spindle-19with a crankdisc22,whilstalength rod24connects these crank members. hearrangement of the elements is such that when the reap stem 15 islowered with its presser-hea 12 forced down to the mould, the latter ismaintained upright, but that dunng the upwanF travel of the stem and assoon as the premer-head is lifted quite clear of the mould, the lastmentioned elementlstiltedtoanangle' 'ngfrom90 to 180 and recovers itsupright position bestem resumes its In the case where a series of theelements of the described conv struction are provided as co-operating,it s preferable to have those moulds slanted one after another in serialsuccession than have them tilted all at once and in the same manner.This serial tilting may be effected by suitably adjusting the relativeangles between the toothed parts of the segment fore the reciprocawheels-and in doing so it is n to adequately fix the segment wheels tothe relative spindles. The corresponding strokes of ,the presser headsmay be accomplished by mountingthe discs 17 on the upper shaft I atsuitable eccentricities. Such an arrangement enables one operator tocontrol at a time a number of moulds by himself.

No sooner has the mould returned to the upright position, than thecutter-casin commences to slide down while a strip 0 sheet rubber isconveyed on to-the mould being actuated by a series of rollers 31. Thecutting element of the cutter-casing now acts, co-operating with theflange of the mould, upon the strip, and cuts it out round at the innerportion whilst a straight cut is being made across the length of thestrip at the rear. Then the motion of the cutter-casing is reciprocatedand goes upwards being accompanied by the simultaneous downward stroke30 .of the presser. In the meantime it is required to remove the sore sof rubber that have been cut off the wor In actual operation, the firstconsists of heating the mould and presser-head to a suitable degree bysteam admitted through the hollow shaft and through the inlet opening onthe presser-head. The next is to place a strip of sheet rubber on therollers provided on the machine bed and so have it conve ed on to themould 'ust at the instant in w 'ch the presser-hea has been lifted clearenough of the latter. Hereupon the cutter-casin will come down and cutthe strip of rub r.round at the inner rtion and straight at the rear ashas described. In no time the presser will be lowered and force theround piece of rubber so cut off down into the mould and therein pressand extend it into a perfectly hemispherical segment of even thickness.Finally the presser will be lifted again and meanwhile the mould will beslanted to an an 10 as from 90 and 180 thereby allowing 'e segment todepart from the mould.

Acco to the invention the operation can be carr ed out with considerablequickness. Moreover, the fact that the segments can bejoined to ther atone place alone, enhances the qua 'ty of the manufacture to a at extent.

aving now particularly described the nature 0 this said invention andascertained the manner in which it is to be performed, I declare thatwhat I claim is:

1. A machine for making rubber articles having a mould surrounded by ajacket to provide a space for a heating medium, a hollow shaft carryingsaid, mould, a hollow presser movable into and out of the mould, and areciprocating cutter having both annular and straight cutting edges.

2. A hollow rubber article manufacturing machine having a mouldsurrounded by a 1 jacket for a heating medium, a hollow shaft carryingsaid mould, a hollow presser above said mould a vertically reciprocatingstem connected with said presser, and a cutter around the saidpresserand provided with both-annular and straight edges, and means toreciprocate "d'cutter.

3; A machine fior making hollow rubber articles comprising twocooperating male and female memberamounted for relative 5 to and fromotion, and an annular cutter surrounding the male member for cutting alglank preliminary to the action of said memers. 4, A machine'for makinghollow rubber 19 articles comprising two cooperating male andfemalemembers mounted for relative to and fro motion, and an annular cuttersurrounding the male member for out 15 a blank preliminary to the actionof sai members, bothsaid members' being hollow to provide spaces for aheating medium.

' In testimony whereof I hereunto aflix my signature. I 20 KENSUKEKUROKAWA.

